Answer:
Sunlight is the greatest source of UV radiation. Man-made ultraviolet sources include several types of UV lamps, arc welding, and mercury vapour lamps.
Explanation:
a.
2. The following examples are good conductors except:
a. Silver
b. Metal
Plastic
d. Copper
Answer:
plastic
Explanation:
Which statement about oceans is incorrect?
A Evaporation occurs when water is warmed by the sun.
B Most evaporation and precipitation occur over the ocean.
C 97 percent of Earth's water is fresh water from the ocean.
D Water leaves the ocean by the process of evaporation.
1. What does the Work-Energy Theorem state?
Work is equal to the change in kinetic energy
Work is equal to the change in momentum
Work is equal to the change in impulse
Work is equal to the change in position
The Work-Energy Theorem states that Work is equal to the change in kinetic energy, which is the first option . This theorem is an essential principle in physics and mechanics, so first option is correct.
Work (W) is a measure of the energy transferred to or from an object by a force acting on it. It is defined as the product of the force applied to the object and the displacement of the object in the direction of the force. When a force does positive work on an object, it transfers energy to the object, increasing its kinetic energy. Conversely, when a force does negative work on an object (opposite to its direction of motion), it takes energy away from the object, decreasing its kinetic energy. So, first option is correct.
Learn more about the work-energy theorem here.
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What is the relationship between CO2 levels and temperature?
What can you infer from this? (make a guess or assumption based on the data)
Approximately what year did the concentration of CO2 first exceed 300 ppm?
Answer:
I can infer that higher levels of CO2 result in warmer temperatures. The CO2 first exceeded 300 ppm in 1950.
Let me know if this helps!
A vertical piston cylinder assembly contains 10.0kg of a saturated liquid-vapor water mixture with initial quality of 0.85 The water receives energy by heat transfer until the temperature reaches 320*C. The piston has a mass of 204kg and area of 0.005m2. Atmospheric pressure of 100kPa acts on the top side of the piston. Local gravitational acceleration is 9.81m/s2 Calculate the amount of heat transfer between the water and the surroundings in kJ. Enter a numeric value only. 6735.66
Answer:
Explanation:
From the given information:
At state 1:
Initial Quality [tex]= x_1 = 0.85[/tex]
mass = 10.0 kg
At state 2:
Temperature [tex]T_2 = 320^0[/tex]
mass of the piston [tex]m_p = 204 \ kg[/tex]
area of the piston [tex]A_p = 0.00 5 \ m^2[/tex]
Atmospheric pressure [tex]P_{atm}= 100 \ kPa = 100 \times 10^3 \ Pa[/tex]
Gravitational acceleration = 9.81 m/s²
[tex]\mathbf{P= P_1=P_2}[/tex], This is because there exists no restriction to the movement of the piston and provided the process is frictionless. So, the process 1-2 is regarded as constant.
To calculate the applying force balance over the piston by using force balance in the vertical direction:
[tex]\mathbf{P_{AP} = P_{atmA_p} + m_pg}[/tex]
∴
(100 × 10³)×0.005 + 204 × 9.31 = P × 0.05
P = 500248 Pa
P = 500.25 kPa
At state 1:
[tex]\mathbf{P_1 = P = 500.25 \ kPa}[/tex]
[tex]x_1 = 0.85[/tex]
Hence, this is a saturated mixture of liquid and vapor
Using the steam tables at 500.25 kPa
[tex]V_f = 1.093 \times 10^{-3} \ m^3/kg \\ \\ V_g = 0.375 \ m^3/kg \\ \\ U_f = 639.72 \ kJ/kg \\ \\ U_g = 2560.72 \ kJ/kg[/tex]
∴
Specific volume at state 1 is given as:
[tex]V_1 = [ V_f +x_1(v_g -v_f) ] \ at \ 500.25 \ kPa \\ \\ V_1 = 0.319 \ m^3/kg[/tex]
volume at state 1 is given by:
[tex]V_1 = mV_1 = 10 \times 0.319 \\ \\ V_1 = 3.19 \ m^3[/tex]
Similarly, the specific internal energy is:
[tex]U_1 = [U_f +x_1 (U_o-Uf)] \ at \ 500.25 \ kPa[/tex]
[tex]U_1 = 639.72 +0.82 (2560.72 -639.72)[/tex]
[tex]U_1 = 2272.57 \ kJ/kg[/tex]
At state 2:
[tex]P = P_1 = P_2 = 500.25 \ kPa \\ \\ T_2 = 320^0 \ C[/tex]
Using steam tables at P = 500.25 kPa and T = 320° C
[tex]V_2 = 0.541 \ m^3/kg \\ \\ U_2 = 2835.08 \ kJ/kg[/tex]
∴
[tex]V_2 = mV-2 = 10 \times V_2 = 5.41 \ m^3[/tex]
[tex]\text{Now; Applying the 1st law of thermodynamics to the system}[/tex]
[tex]_1Q_2 -_1W_2 = \Delta V =m(u_2-u_1) \\ \\ where;\ _1W_2 = P(V_2-V_1) \\ \\ _1Q_2 -P(V_2-V_1) = m(u_2-u_1) \\ \\ _1Q_2 - 500.25(5.91 -3.19) = 10( 2835.08 -2272.57) \\ \\ \mathbf{ _1Q_2 = 6735.66 \ kJ}[/tex]
The idea is to get as much EMF produced from the sprinter running through it. If you were the Olympic coach on a year when there happens to be a global energy crisis, and medals were assigned based on how much EMF (or current) were produced by the sprinters, what 3 pieces of advice (one is quite obvious; the other two involve the fixed orientation of the baton and the maintained position of the baton within the circular solenoid cross-section) would you give your sprinters in order to win?
Answer:
the greater the speed, the greater the electromotive force
* The metal pole must be parallel to the field
* you must keep the ball of the field
Explanation:
To determine the advice to the runners, let's use the Farad equation to and
fem = -N [tex]\frac{ d \phi}{dt}[/tex] = -N [tex]\frac{ B A Cos \theta }{dt}[/tex]
how the runners are moving
fi = B l x
fem = -N B l v
therefore the advice we can give are:
* the greater the speed, the greater the electromotive force
* The metal pole must be parallel to the field
* you must keep the ball of the field
NEED HELP PLEASE
ASAP
SOMEONE!!!!!!!!
TRUE OR FALSE 3 QUESTIONS
OWA OWA :3
Answer:
8. True
9. true
10. false
Explanation:
Answer:
false
true
false
the galaxies are moving away from each other, not towards each other.
An object which is dropped from a certain height has zero (0) initial velocity.
Answer:
0 m/s
Explanation:
if an object is dropped we know the initial velocity is zero when in free fall
an austrain who lived in vienna who composed graetest music for waltz dance
A boy kicks a football with a force of 20 N, the time the force acts for is 0.3s. Calculate the impulse on the ball.
Answer:
20 * .3 = 6N
Explanation:
The impulse on the ball kicked with a force of 20 N force 0.3 s is 6 Ns
From the question given above, the following data were obtained:
Force = 20 N
Time = 0.3 s
Impulse = ?The impulse on the ball can be obtained as follow:
[tex]impulse \: = force \: \times time \\ impulse \: = 20 \: \times \: 0.3 \\[/tex]
Impulse = 6 NsTherefore, the impulse on the ball is 6 Ns
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In a thunderstorm at 32.0°C, Reginald sees a bolt of lightning and hears the thunderclap 2.00s later. How far from Reginald did the lightning strike? The speed of sound through air at 32.0°C is 350.2 m/s. Show your work.
PLEASE HELP, THANKS!
Answer:
d = 700.4 m
Explanation:
Given that,
The speed of sound through air at 32.0°C is 350.2 m/s.
Reginald sees a bolt of lightning and hears the thunderclap 2.00s later.
We need to find how far from Reginald did the lightning strike. Let the distance be d. So,
Speed = distance/time
d = vt
So,
d = 350.2× 2
d = 700.4 m
So, the required distance is 700.4 m.
A centrifuge is a device used to separate materials by their masses. A sample in a centrifuge is rotated at high speeds along a circular path a distance of 10.0 cm from the center of the centrifuge. A centrifuge constantly accelerates a 1.00-gram sample from rest to a speed of 1,000 revolutions per minute in 1.00 seconds. Eventually, the sample reaches a speed 10.5 m/s. What is the magnitude and direction of the centripetal force acting on the sample
Answer:
F = 1.047 10⁻² N
Explanation:
Let's use kinematics to find the angular acceleration
w = w₀ + α t
as for rest w₀ = 0
w = α t
α = w / t
let's reduce the magnitudes to the SI system
w = 1000 rev / min (2π rad/ 1 rev) (1 min/ 60s) = 104.72 rad / s
m = 1.00 g (1 kg / 1000 g) = 1,000 10⁻³ kg
r = 10.0 cm (1 m / 100 cm) = 0.100 m
let's calculate
α = 104.72 / 1
α = 104.72 rad / s²
angular and linear variables are related
a = α r
a = 104.72 0.100
a = 10.47 m / s²
finally we substitute in Newton's second law
F = 1 10⁻³ 10.47
F = 1.047 10⁻² N
A truck of mass 1600 kg is traveling at 15 m/s. In order to avoid running over a squirrel in the middle of the road, the truck driver begins to brake. What must the braking force on the truck be if the truck comes to stop in 2 s? *
a)12000n
b) 8000n
c)7000n
d)6000n
Which type of electricity is a one-time event, caused by unbalanced charges trying to become neutral again?
Answer: yes
Explanation:
Someone pls help!! Right now :(
8. What is the mass of a toy car with a speed of 12.5 m/s and 47500 J of kinetic energy?
Answer:
608kg
Explanation:
Formula : Kinetic energy
½ ×mass x speed²
47500
½×12.5²
=608 Kg
During which sequence of phases does the moon's visibility increase
During the "waxing" phases, the two weeks immediately following the New Moon.
New Moon ==> waxing crescent ==> First Quarter ==> waxing gibbous ==> Full Moon
The phase of the moon decides the moon's visibility. The sequence of phases does the moon's visibility increases is; the waxing crescent, first quarter, waxing gibbous, full Moon.
What is the moon phase?The moon changes shape every day. This is due to the fact that the celestial body has no light of its own and can only reflect sunlight.
Only the side of the moon facing the sun can reflect this light and seem bright. The opposite side appears black. this is a full moon.
We can only see the black section when it lies between the sun and the earth when a new moon occurs. We witness intermediate phases like a half-moon and crescent in between these two extremes.
Following are the sequence of phases does the moon's visibility increase is;
1. Waxing crescent
2. First Quarter
3. Waxing gibbous
4. Full Moon
The phase of the moon decides the moon's visibility. Hence the visibility changes with the change in the phase of the moon.
To learn more about the moon's phase refer to the link;
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a force is applied to the right to drag a sled to the right across Loosely packed snow with a rightward acceleration (considered friction forces)
Answer:
1.67 m/s²
Explanation:
Total force is;
ΣF = F_f + F_a
From the free body diagram attached, we see that the frictional force F_f is acting in a negative direction.
Thus;
ΣF = -15 + 30
ΣF = 15 N
Now, to get the acceleration, we will use the formula;
ΣF = ma
We are given m = 9 kg
Thus;
15 = 9a
a = 15/9
a = 1.67 m/s²
Who watching all star draft? Luka better get picked first ong
a skydiver is falling down through the air but has not reach terminal velocity (not consistent velocity )(considered air resistance)
We are to find the acceleration.
Answer:
-9.2 m/s²
Explanation:
Total force is expressed as;
ΣF = F_d + F_g
We are given;
F_d = 50 N
Mass of skydiver = 78 kg
Thus, F_g = 78 × -9.8
g is negative since it is a free fall
Thus;
F_g = -764.4 N
ΣF = 50 - 764.4
ΣF = -714.4 N
Formula for acceleration is;
ΣF = ma
a = -714.4/78
a ≈ -9.2 m/s²
The rate at which work is done is known as which of the following?
A. Power,
B. Energy,
C. Momentum,
Answer:
A , power
Explanation:
Hope this is useful. Have a lovely rest of your day! God bless you.
Which would be a good analogy of wave motion
Answer:
i believe it would be C
Explanation:
Calculate wavelength of tube of length 15, 18, 20 cm.
Answer:In this lesson, the mathematical relationship between the tube's length, the speed of sound through air, and the ... Thus, the length of the air column is equal to one-half of the wavelength for the first harmonic. ... Determine the fundamental frequency (1st harmonic) of an open-end air column that has a length of 67.5 cm.
Explanation:
What is the earliest time at which the oscillator shown below is stationary?
Answer:
0.0s
Explanation:
I got it right in acellus
Answer: 0.0
Explanation:
Physics help, thank you guys so much!
Answer:
Δt = 5.85 s
Explanation:
For this exercise let's use Faraday's Law
emf = [tex]- \frac{d \phi}{dt}[/tex] - d fi / dt
[tex]\phi[/tex] = B. A
\phi = B A cos θ
The bold are vectors. It indicates that the area of the body is A = 0.046 m², the magnetic field B = 1.4 T, also iindicate that the normal to the area is parallel to the field, therefore the angle θ = 0 and cos 0 =1.
suppose a linear change of the magnetic field
emf = - A [tex]\frac{B_f - B_o}{ \Delta t}[/tex]
Dt = - A [tex]\frac{B_f - B_o}{emf}[/tex]
the final field before a fault is zero
let's calculate
Δt = - 0.046 (0- 1.4) / 0.011
Δt = 5.85 s
A magnet produces a magnetic field.
Which diagram shows the magnetic field pattern around a bar magnet
You Forgot To Add The Pictures
How does changing the frequency affect the sound that you hear?
Answer:
It leads to a higher pitch of sound which means the sound is louder.
Explanation:
When a sound is made, it will cause vibrations to occur.
The size of these vibrations are called amplitude while their speed is called frequency.
Now, the larger the vibrations implies that we will have high amplitude such that the sound is louder, whereas, the higher the frequency, the higher the pitch of sound and vice versa.
The larger the pitch, the louder the sound and vice versa.
Thus, increasing the frequency leads to higher pitch and ultimately louder sound.
a guitar string transmits waves at 509 m/s. to create a 491 Hz note, to what length should the guitar player shorten the string?
Answer:
Wavelength = 1.04 meters
Explanation:
Given the following data;
Speed = 509m/s
Frequency = 491Hz
To find the wavelength;
Wavelength = speed/frequency
Wavelength = 509/491
Wavelength = 1.04 meters
Therefore, the guitar player should shorten the length of the string to 1.04 meters.
Answer: 0.52
Explanation:
Which of the following is an example of kinetic mechanical energy?
Immersive Reader
(2 Points)
A. A bike rolling down a hill
B. An elevated wrecking ball
C. A compressed spring
D. A loaded gun
E. A set mouse trap
Answer:
A
Explanation:
Kinetic energy must be moving. Potential energy has the ability to move but is not doing so at the moment.
A is likely the answer. But there's lots involved in that kind of motion.
B If the ball is elevated, it implies it is not moving yet. It has potential energy.
C Again, the spring is compressed. It will push something when it moves, but it is not moving yet.
D The load gun's bullet is not moving. It's still potential energy.
E. The mouse trap is set, but it is not moving. When the mouse eats the bait then it's potential energy will transform into kinetic energy.
10POINTS!!
A satellite orbits Earth 350 km above Earth's surface. Calculate the free-fall acceleration at this altitude.
Answer:
8.82 m/s²
Explanation:
Formula for the free fall or gravitational acceleration is;
a = GM/r²
Where;
G is gravitational constant = 6.67 × 10^(-11) m³/kg.s²
M is mass of earth = 5.972 × 10^(24) kg
r is radius of earth = 6371 km
We are given that the satellite orbits Earth 350 km above Earth's surface.
Thus, new radius = 6371 + 350 = 6721 km = 6721000 m
Thus;
a = (6.67 × 10^(-11) × 5.972 × 10^(24))/(6721000²)
a = 8.82 m/s²